Field of the Invention
The present invention relates to an image processing apparatus and an image processing method.
Description of the Related Art
Image pickup apparatus having a function of photographing a moving image in addition to a function of photographing a still image have appeared as recent digital single-lens reflex cameras. Some of the digital single-lens reflex cameras have a function of enabling still-image photographing during moving image photographing. Further, a digital camera capable of photographing a moving image generally includes a liquid crystal display mounted on a back surface thereof. A photographer can photograph a subject which is a target to be photographed while observing the subject through the liquid crystal display mounted on the back surface.
Further, there is known an autofocus (hereinafter referred to as “AF”) technology of automatically performing a focus adjustment operation for focusing on a predetermined region when a moving image and a still image are photographed. The AF technology is roughly classified into a phase detection AF technology and a contrast AF technology.
The phase detection AF is an autofocus method of splitting a light flux which enters through a lens and detecting a phase shift between images respectively generated by she light fluxes so that focus is adjusted in accordance with the detected phase shift. In Japanese Patent No. 4027113, there is disclosed a technology of forming a plurality of photoelectric conversion units for each pixel to perform pupil-division on an image pickup plane so as to realize the phase detection AF.
The contrast AF is an autofocus method of acquiring an image while moving a lens and driving the lens using a lens position at which an amplitude of contrast of the image has a peak as a point of focus.
There is also known a technology capable of obtaining (recomposing) an image which is in focus on a point at a different distance in the same depth of field, from image data obtained by single photographing. In Japanese Patent Application Laid-Open No. 2007-4471, there is disclosed a technology of photographing light fluxes passing through different regions of an exit pupil of an imaging optical system and then combining image data respectively obtained by the light fluxes passing through the different regions so as to generate image data of an image on an arbitrary image plane by single photographing.